ASHEVILLE, N.C. — Moonestone Stout glimmered in the glass when I lifted it to the light. I wondered what I'd taste. Five other tasters took their first sips and nodded their heads. It was smooth, richer than it looked and good with a capital G.

We'd been told the brewer boiled 5 pounds of oysters in the brewing, shell and all. They said the oysters added sea salt, calcium and other minerals to the flavor. I took another sip, still good.

OysterHouse Brewing Co., a nano-brewery on the Asheville Brews Cruise, brews just enough beer to serve at its home base, The Lobster Trap restaurant.

The Brews Cruise takes guests behind the scenes to sample, learn how beers are made and talk to brewmasters. In less than a mile's walk, we visited four breweries — Craggie Brewing Co., Green Man Brewing, OysterHouse Brewing Co. and Asheville Brewing Co. — tasting three to five samples at each. Our guide, Delaney Downer, explained how combining hops, malt, yeast and occasionally other ingredients could turn water into a drink that would sustain life, or at least make it better.

Craggie is known for adventurous flavors. Its Antebellum Ale had an undertone a little like molasses cookies, only better. Inspired by beer recipes from the Civil War, Antebellum's ingredients include spruce, ginger and molasses. We also got a bite of Antebellum ice cream, rich and creamy with an echo of hops.

The beers from Green Man Brewery tend toward traditional British-style ales with an emphasis on hops. We tasted at the original brewery in Jack of the Wood, a Celtic pub where musicians played Irish tunes in the background. My favorite brew was the on-cask Porter, for its appealing smoothness and roasted coffee finish.

The tour started and ended at Asheville Brewing Co., where locals hang out for food, music and beer. Our group agreed that the sharp hoppiness of ABC's flagship Shiva IPA would be a good foil for a plate of peppery nachos.

Complexity and variety perhaps should be a given in a city that's home nine craft breweries, a surprising large number for a town of about 80,000. No wonder the town wears the title of BeerCity USA.